Creation of functionalized microparticle libraries by oligonucleotide ligation or elongation

ABSTRACT

Disclosed are methods of for constructing a bead-displayed library of oligonucleotide probes (or sequence-modified capture moieties such as protein-nucleic acid conjugates) by ligation of a capture probe, having an analyte-specific sequence, to an anchor probe that is attached, at its 5′-end, (or possibly at the 3′ end) to an encoded carrier such as a color-coded microparticle (“bead”). Such a library can also be constructed by elongation of an anchor probe, using a second probe as the elongation template, wherein the second probe has an anchor-specific subsequence and an analyte-specific subsequence.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser. No. 60/686333, filed Jun. 1, 2005.

BACKGROUND REFERENCES All Incorporated by Reference

The following can be referred to as background in order to aid in understanding of certain of the terms and expressions below.

-   “Oligo-Ligation via nick sealing”—Cherepanov, A. V. and de Vries, S.     Kinetics and thermodynamics of nick sealing by T4 DNA ligase.     Eur. J. Biochem., 270, 4315-4325 (2003). -   “Chemical Ligation”—Xu, Y. and Kool, E. T. High sequence fidelity in     a non-enzymatic DNA autoligation reaction. Nucleic Acids Research,     1999, vol. 27, no. 3, 875-881. -   “Ligation based SNP detection”—Dubiley, S. et al. Fractionation,     phosphorylation and ligation on oligonucleotide microchips to     enhance sequencing by hybridization. Nucleic Acids Research, 1997,     vol. 25, No. 12, 2259-2265. -   “Sequencing via cleavage and ligation”—Brenner, S. et al. In vitro     cloning of complex mixtures of DNA on microbeads: Physical     separation of differentially expressed cDNAs. Proc. Natl. Acad. Sci.     USA, vol. 97, no. 4, 1665-1670 (2000). -   Hermanson, G. T. 1996. Bioconjugate Techniques, Academic Press, San     Diego, Calif. Liu, P., Burdzy, A., Sowers, L. C. “DNA ligases ensure     fidelity by interrogating minor groove contacts” Nucleic Acids Res.     32, 15, 4503-4511 (2004). -   Broude, N. E., Sano, T., Smith, C. L., Cantor, C. R. “Enhanced DNA     sequencing by hybridization” Proc. Natl. Acad. Sci. USA, Vol. 91,     3072-3076 (1994). -   Iannone, M. A et al. “Multiplexed Single Nucleotide Polymorphism     Genotyping by Oligonucleotide Ligation and flow cytometry”,     Cytometry 39 : 131-140 (2000). -   Gerry, N. P. et al. “Universal DNA microarray method for multiplex     detection of low abundance point mutations”, J. Mol. Biol. 292,     251-262 (1999).

BACKGROUND DISCUSSION

The functionalization of solid phase carriers, notably microparticles (“beads”), for chemical and biological analysis, is generally is accomplished using a variety of covalent conjugation chemistries, including the EDAC-mediated reaction (see Hermanson, G. T. 1996. Bioconjugate Techniques, Academic Press, San Diego, Calif., incorporated by reference). Libraries of encoded functionalized microparticles for use in multiplexed formats of interrogation of nucleic acid sequence configurations—for example, those discussed in U.S. Pat. No. 6,797,524 and U.S. patent application Ser. No. 10/032,657, filed Dec. 18, 2001 (both incorporated by reference) which use the Random Encoded Array Detection (READ™) format, where a bead array is formed on a substrate (a “BeadChip™”)—generally comprise a multiplicity of bead types, distinguishable, for example, by color, each type displaying one analyte-specific capture sequence. Analogous considerations apply to libraries of bead-displayed capture moieties (“receptors”) for use in the multiplexed capture of proteins (“ligands”).

Functionalization by covalent attachment requires the chemical modification of each analyte-specific capture probe, for example by amination of the 5′-end using amine-modified dNTP's and appropriate linker moieties, for attachment to carrier-displayed carboxyl groups in the standard EDAC-mediated reaction (Hermanson G. T, supra). Oftentimes such immobilization protocols lead to improper orientation and steric hindrance problems, most of which can be removed by introduction of spacer molecules. While widely practiced, these chemical modifications nevertheless require special purification, usually by HPLC, and this purification step lowers the yield, raises the cost, and delays procurement. Further, each analyte-specific capture probe sequence is exposed to the not always gentle conditions of the attachment reaction which may introduce damage to the capture moiety, the degree of which may be difficult to assess. In addition, from a regulatory point of view, each modified carrier may be considered a separate reagent, requiring separate qualification.

From the point of view of manufacturing of encoded solid phase carriers, it will be beneficial to have a method of producing functionalized encoded microparticle libraries, where the microparticles bear a designated probe coverage (i.e., the number of probes/bead surface area) without the need for elaborate chemical modification of the analyte-specific capture probe sequences. Further, less chemical modification is more desirable from a regulatory point of view.

SUMMARY OF THE INVENTION

The present invention discloses a method for constructing a bead-displayed library of oligonucleotide probes (or sequence-modified capture moieties such as protein-nucleic acid conjugates, see U.S. application Ser. No. 10/227,012, incorporated by reference) by ligation of a capture probe, having an analyte-specific sequence, to an anchor probe that is attached, at its 5′-end, (or possibly at the 3′ end) to an encoded carrier such as a color-coded microparticle (“bead”). In one embodiment, an array of color-encoded microparticles configured in accordance with the READ™ format of multiplexed analysis (see U.S. Pat. No. 6,797,524, incorporated by reference) may be functionalized in a single on-chip reaction.

In another embodiment, a library of oligonucleotide probes (or sequence-modified capture moieties such as protein-nucleic acid conjugates, see U.S. application Ser. No. 10/227,012) is generated by elongation of an anchor probe, using a template probe having an analyte-specific subsequence and an anchor probe-specific subsequence. The anchor probe is attached, at its 5′-end, to an encoded carrier such as a color-coded microparticle (“bead”). The template probe is annealed through the anchor probe-specific subsequence, and the anchor probe is elongated with deoxynucleotide tri-phosphate (dNTPs) complementary to the analyte-specific subsequence to generate an elongation product, capable of capturing the analyte (see U.S. application Ser. No. 10/271,602, for a description of the elongation process, incorporated by reference.)

In yet another embodiment, a library of bead bound oligonucleotide probes (or sequence-modified capture moieties such as protein-nucleic acid conjugates) is generated by either ligation or elongation as described above. However, in this case, the anchor sequence in addition to serving as an address sequence for the capture probe of interest is also utilized as a decode sequence. In this embodiment thus each bead type is defined by a combination of its fluorescent encoding as well as the unique anchor sequence attached to it that is recognized by a complementary decoder. The complementary decoder can be for example, a fluorescently labeled complementary oligonucleotide.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts the bead, with an anchor oligo attached and “clamped” to a capture oligo with a unique subsequence capable of hybridizing with a particular target.

FIG. 2A depicts generating a library of capture oligo functionalized beads using the ligation methods herein.

FIG. 2B depicts generating a library of capture oligo functionalized beads using the ligation methods herein

FIG. 3 depicts the process of converting a BeadChip™ displaying anchor-oligo functionalized bead array to an analyte specific bead array using methods herein.

FIG. 4 depicts an in-solution ligation of probes 1 and 3 (with and without ligase), followed by attachment of the ligated product to a bead, removal of the clamp, and detection of the ligated product.

FIG. 5 depicts attachment of an anchor probe to a bead, followed by ligation of an analyte-specific probe 3, with and without ligase, removal of the clamp, and detection of the ligated product.

FIG. 6 depicts a summary of an experiment demonstrating multiplexed ligation. The analyte-specific probes 3, 6 and 9 are shown to be ligated in a specific manner via hybridizations to their labeled respective targets 4, 7 and 10.

FIG. 7 depicts a summary of an experiment demonstrating that the hybridization performance of ligated and covalently coupled analyte specific probe are comparable.

FIG. 9 shows making an encoded bead with a capture oligo with a unique subsequence capable of hybridizing with a particular target, using hybridization-mediated elongation rather than ligation.

DETAILED DESCRIPTION

In one embodiment, encoded carriers are functionalized in two steps, namely: a first step of covalently attaching to a multiplicity of carriers an “anchor” probe having a sequence that generally is unrelated to any of the analyte-specific sequences; and a second step of ligating, to the anchor sequence on a given carrier type, a capture probe having an analyte-specific sequence that is recognizably associated with the carrier code. The step of ligating the two probes can be catalysed by a DNA ligase. The ligation is achieved by using a third clamp-probe which has a sequence so as to allow hybridization of the anchor and capture probe immediately adjacent to each other. The temporary hybridization complex in which anchor and capture sequences are annealed immediately adjacent to one another to the clamp, thereby form a duplex with a “nick” which can be sealed by a ligase-catalyzed formation of a phosphodiester bond between the 3′ hydrodxyl group of the anchor sequence and the 5′ phosphate group of the capture sequence (Cherepanov, A. V. and de Vries, S. Kinetics and thermodynamics of nick sealing by T4 DNA ligase. Eur. J. Biochem., 270, 4315-4325 (2003)) to produce a single oligonucleotide (FIG. 1). In another embodiment, chemical ligation also may be used (Chemical Ligation; Hermanson, G. T. 1996. Bioconjugate Techniques, Academic Press, San Diego, Calif.; Xu, Y. and Kool, E. T. High sequence fidelity in a non-enzymatic DNA autoligation reaction. Nucleic Acids Research, 1999, vol. 27, no. 3, 875-881). The use of this ligase-catalyzed reaction in several diagnostic applications, notably in a solid phase format, has been previously described. Examples include the reliable detection of a single-nucleotide polymorphism (SNP) or mutation at the site of the “nick” (Dubiley, S. et al., supra), microsequencing (Brenner, S. et al., supra).

In all such applications, DNA ligase is utilized to produce a covalent phosphodiester bond between the bead bound probe (carrying a 3′ hydroxyl group) and the target oligonucleotide strand (carrying a 5′ phosphate group). The methods rely on the fact that DNA ligases are sensitive to mis-paired nucleotides (mismatches) present on the 3′ side of the ligated junction but somewhat tolerant of mismatches on the 5′ side [Liu, P., Burdzy, A., Sowers, L. C. “DNA ligases ensure fidelity by interrogating minor groove contacts” Nucleic Acids Res. 32, 15, 4503-4511 (2004)]. This requirement that DNA ligases need fully base-paired duplexes near to the DNA junction has also been exploited to improve the performance of sequencing by hybridization [Broude, N. E., Sano, T., Smith, C. L., Cantor, C. R. “Enhanced DNA sequencing by hybridization” Proc. Natl. Acad. Sci. USA, Vol. 91, 3072-3076 (1994)] multiplexed SNP detection [Iannone, M. A et al. “Multiplexed Single Nucleotide Polymorphism Genotyping by Oligonucleotide Ligation and flow cytometry”, Cytometry 39 : 131-140 (2000)] and for multiplexed detection of low abundance point mutations via a polymerase chain reaction/ligation detection reaction followed by hybridization to “zip-code” array [Gerry, N. P. et al. “Universal DNA microarray method for multiplex detection of low abundance point mutations”, J. Mol. Biol. (1999) 292, 251-262].

Herein, ligation is applied to a different purpose, namely the creation of a library of functionalized solid phase carriers, and especially of functionalized encoded microparticles (“beads”).

In one embodiment of the method, some or all of the carrier types selected for the library may display the same anchor sequence. Thus, a set of carrier types displaying the same anchor sequence would constitute a general purpose reagent which could be converted by the method of the invention to acquire analyte specificity. That is, by using clamps having sequences complementary to the same anchor sequence but different capture sequence, the same set of carrier types is readily functionalized in different ways. Further, two sublibraries containing carriers having identical color code, but displaying anchor probes of different sequence, may be mixed and decoded via interrogation of anchor sequences (that is, the anchor sequences function as an additional means by which to encode the array, which is decoded by annealing of the unique complementary sequence).

In another embodiment, this method also permits the creation, in a single-tube reaction (FIG. 2), of an entire library of carrier-displayed probe sequences, each carrier type within the library being associated with an anchor probe having a type-specific sequence. Similarly, an assembled planar array composed of multiple color-coded types of beads, each type displaying an anchor probe having a type-specific sequence (see FIG. 3) could be converted to an analyte specfic array via the ligation protocol disclosed herein. From a manufacturing point of view, this method would permit the order of array assembly and carrier functionalization to be reversed thereby permitting functionalization to be performed, either in a wafer-scale format, or in a chip-scale format, in a manner limiting the amount of reagent consumed. See U.S. application Ser. No. 10/192,352, regarding wafer-scale and chip-scale assembly. From a regulatory point of view, the advantage of such an approach would be to be able to classify the assembled array as a general-purpose reagent. Specifically, the on-chip conversion of this general-purpose array into an application-specific array, calls for three reagents, two general-purpose reagents, namely the array displaying the set of anchor probes and a set of clamps, and a set of analyte-specific reagents, namely the capture probes. The assembled array will be composed of multiple types of beads with type-specific anchor sequences. Clamps will have one subsequence that is complementary to an anchor-sequence and one subsequence that is complementary a portion of the sequence of the capture probe. The third reagent namely the capture probe, will be an analyte-specific reagent (ASR). In one embodiment, the capture probe will have a portion that interacts with the target and another portion that interacts with the clamp.

In another embodiment, the on-chip conversion of the general-purpose array into an application-specific array is performed not by ligation but by a polymerase-catalyzed elongation reaction using the analog of a clamp sequence as an elongation template. That is (see FIG. 8), as before, the 3′-end of the clamp sequence is designed to form a duplex with a specific anchor sequence displayed on an encoded microparticle under conditions permitting the elongation of the anchor sequence in a manner described in U.S. application Ser. No. 10/271,602 (incorporated by reference), but not necessarily with incorporation of fluorescently tagged dNTPs pr ddNTPs. The “overhang” of the template, typically 10-30 nt and more typically 15-25 nt in length, is selected to be identical to a specific target sequence of interest. Elongation adds to the 3′ end of the anchor sequence an application-specific subsequence that is complementary to the 5′-overhang of the template sequence (see U.S. application Ser. No. 10/271,602). Following completion of the elongation reaction, the template and reaction constituents are removed (for example by washing in water, at elevated temperature). In contrast to the ligation-catalyzed method, no capture probe sequence is needed, a fact that simplifies the design of “orthogonal” sequence sets (see also Example 8). Multiple elongation reactions can be performed in parallel, permitting the concurrent modification of an entire set of arrays. The availability of a general-purpose bead array permits a mode of co-development. Manufacturing generally will require facilities which will not be available to prospective users of the array who might wish to provide their own array composition for specific applications. The methods described herein provide for the separation of the step of array manufacturing—including the synthesis of a general-purpose library of encoded beads, the assembly of bead arrays and their packaging into desired configurations—from the step of rendering the array application specific. The methods of array modification disclosed herein thus facilitate a modality of co-development by which the array manufacturer provides a set of reagents including the general-purpose array, as well as application-specific reagents such as the template sequence, in the case of the elongation-mediated method of the invention, and application developers produce application-specific arrays “as-needed.” The array manufacturer thereby can engage in strategic co-development projects and collaborations while retaining control over technical know-how, while enabling the application developer to likewise retain control of sensitive information and permitting “on-site” experimentation with different sequences in a prototyping mode requiring rapid turn-around. The methods of the invention thereby permit the array manufacturer to extend the range of application of pre-assembled arrays.

EXAMPLES Example 1 Synthesis and Design of Oligonucleotide Sequences

All oligonucleotide synthesis was carried out by IDT (Coralville, Iowa). The sequence information and the end modifications are shown in Table 1. TABLE 1 Oligo# Olgio Name Sequence (5′-3′) 1 DR-70e-Biotin Biotin-TEG-CAG AAG GAC ATC CTG GAA G 2 LK-70e-HA114 TCG GTC TTC CAG GAT 3 P-HA114 PO₄ ⁻- ACC GAG AGA GCC TGC GGA T 4 T-HA114 Cy3-ATC CGC AGG CTC TCT CGG T 5 LK-70e-HA107 TCC TGC TTC CAG GAT 6 P-HA107 PO₄ ⁻-CAG GAG AGG CCT GAG TAT T 7 T-HA107 Gy3-AAT ACT CAG GCC TCT CCT G 8 LK-70e-HA125 CGC CTC TTC CAG GAT 9 P-HA125A PO₄ ⁻-AGG CGG TCC ATG CGG C 10 T-HA125A Cy3-GCC GCA TGG ACC GCC T 11 DR-70e-Amine Amine-TEG-CAG AAG GAC ATC CTG GAA G 12 P-HA114-Amine Amine-TEG-ACC GAG AGA GCC TGC GGA T

Example 2 In-Solution Ligation Followed by Capture of Ligated Product on Bead

For this example oligos 1, 2 and 3 were used. Hybridization was performed by mixing 5 ul aliquots of 10 uM oligo 1, 2 and 3 in solution, heating the solution to 95° C., holding for five minutes and slowly cooling it back to room temperature. Ligation was carried out at RT for 2 hours by taking 5 ul of the hybridization mix and adding to it 2 ul of 10× T4 Ligase Reaction buffer (supplier info) and 1 ul of T4 ligase enzyme. The reaction volume was made to 20 ul by addition of 12 ul of deionized molecular biology grade water. The biotinylated reaction product was captured using color-encoded Neutravidin functionalized beads. 10 ul of 1% beads was added to 20 ul of the ligation reaction product and the reaction volume adjusted to 350 ul by adding 1×PBS. The suspension was incubated at room temperature for 30 minutes with shaking. Following capture reactions, the beads were washed 2× with PBST and re-suspended in 10 ul PBS. The beads were then assembled, on chip, and the hybridized duplex was disrupted and the clamp-oligo removed via a stringent wash at 53° C. (wash buffer:m20 mM TRIS, pH 7.5, 0.1× SSC, 0.01% SDS). Finally the detection of the ligated product was carried out via hybridization by using a series of dilutions of the labeled probe 4 in 1×TMAC. The hybridization was carried out using 20 ul of solution/chip, at 53° C. for 25 minutes. Post hybridization washing was performed using 0.7×TMAC and at 53° C. Finally the Chip was mounted on to the BAS AIS system and the fluorescent images recorded. The results are shown in FIG. 4.

Example 3 On-Bead Ligation

The experiment was identical to Example 1, except the anchor sequence (#1) was immobilized on a Neutravidin functionalized color encoded bead first. The ligation was hence carried out using the ternary hybridization complex (oligos 1+2+3) tethered to the bead. The results are shown in FIG. 5.

Example 4 Multiplexed on Bead Ligation

Two pairs of particle captured ternary hybridization duplexes were produced using methods outlined in Example 1 and 2.

-   Pair 1: oligos (1+2+3) and oligos(1+5+6) and -   Pair 2: (1+2+3) and (1+8+9) (each prepared separately).     On-bead ligation reaction was performed as disclosed above followed     by stripping off clamp oligos 2 and 5 (pair 1) and oligos 2 and 8     (pair 2). Finally the presence and specificity of the ligated probes     was checked via separate hybridizations with labeled targets 7 and 4     (pair 1) and labeled targets 10 and 4 (pair 2). The results are     shown in FIG. 6.

Example 5 Comparison of Chemically Coupled and Ligated Analyte-Specific Capture Probes

5′ aminated probes 11 and 12 were coupled to two different color encoded particles using an EDAC reaction under nominally identical conditions. The bead coupled with probe 12 was subjected to ligation using clamp and capture oligos 2 and 3, respectively. The bead coupled with probe 12 was directly used for target (No. 4) detection via hybridization. The results are shown in FIG. 7.

Example 6 Oligonucleotide Design for Multiplex On-Chip Ligation

A number of different computer programs are available for design of oligonucleotides to be used as PCR primers, molecular beacons or other applications. For each application a different set of constraints need to be imposed on the design process. No existing software to the best of our knowledge, provides designs or constraints suitable for use with the ligation or elongation products described herein. This example describes the design process for a set of anchor, clamp and capture probes for use in multiplexed on-chip ligation.

The function of the ss-anchor oligo is to interact with its perfect complement (clamp) and not to bind any other oligo in solution. A significant amount of scientific literature is available on the design algorithms of such non-interacting tag sequences (Gerry, N. P. et al. Universal DNA microarray method for multiplex detecion of low abundance point mutations. J. Mol. Biol. (1999) 292, 251-262; Liu, Q. et al. DNA computing on surfaces. Nature (2000) 403,175-178). For the current study we chose to use two sets of published tag sequences. The first set (30 sequences) was obtained from the genome website at Massachusetts Institute of Technology. The tags were 25-27 bases in length, T_(m) ˜55° C. at a salt conc. of 50 mM and contained no more than two consecutive identical bases. The tags were checked using BLAST and found non homologous to all known human genes. The second set (13 sequences) was collected from a published set of GeneFlex™ Tag Array sequence collection (Affymetrix, Santa Clara, Calif.) that contains sequence information for 2000 oligonucleotides with minimal tendency for cross-hybridization. The sequences were 20 bases long.

The function of the ss-capture oligo is to interact with the cognate target and the clamp sequence and not bind any other oligo in solution. The choice of the capture sequence is determined by the assay of interest. For this example a set of probes for the HLA DQ locus was selected. As described above, since the sequence tags are unrelated to the particular set of probes (targeting a human gene) in question the approach is generic and can be used for any set.

Once a potential pool of anchor sequences and a set of capture sequences were chosen (see Table 3), the anchor sequences were checked for their 3′ similarity. The sequences which had 3′ similarity were identified and flagged (see Table 4). Next the capture sequences were checked for their similarity in the first 5 bases from the 5′ end. If found, similar additional bases were inserted at the 5′ end and the check repeated, until all the 21 probes had unique 5′ ends. The process left the starting capture sequences minimally perturbed and a maximum of two additional 5′ base insertions were needed see Table 5). Finally the set of all the tag sequences were checked for homology with the probe sequences and their reverse complements. TABLE 3 List of anchor probe and capture probe sequences List of anchor probe sequences B1 CGCAGGTATCGTATTAATTGATCTGC A1 GTTGATGTCATGTGTCGCAC B2 CCTCATGTCAACGAAGAACAGAACC A2 TCGTGCCTTGTCATTCGGGA B3 ATTGAAGCCTGCCGTCGGAGACTAA A3 CGTGCAAGTTACCGAGCTGA B4 AGACTGCGTGTTGGCTCTGTCACAG A4 TAGATCAGTTGGACTCGATG B5 TTATGGTGATCAGTCAACCACCAGG A5 GCAGGGAATTGCCGACCATA B6 GAGACACCTTATGTTCTATACATGC A6 ACGTTCGTCAAGAGTCGCAT B7 TCCATGCGCTTGCTCTTCATCTAGC A7 CGTTCCTAAAGCTGAGTCTG B8 GCCTTACATACATCTGTCGGTTGTA A8 GAGAGGCCGTCGCTATACAT B9 CACAAGGAGGTCAGACCAGATTGAA A9 AAGCCAGATCGACCATCGTA B10 GCCACAGATAATATTCACATCGTGT A10 GACGCCGTTATGAGAGTCCA B11 ACACATACGATTCTGCGAACTTCAA A11 ATATCGTGTCACAGGTCGTT B12 TTACAGGATGTGCTCAACAGACGTT A12 ATGATGTGCAAAGTGCCGTC B13 GCTCACAATAATTGCATGAGTTGCC A13 TCCGTCTGTTGAGTTAGGCC B14 CTGCACTGCTCATTAATATACTTCTGG A14 CTCGACCGTTAGCAGCATGA B15 TTCACGCACTGACTGACAGACTGCTT A15 CCGAGATGTACCGCTATCGT B16 CAACATCATCACGCAGAGCATCATT A16 AGAGCGCATGAATCCGTAGT B17 GCATCAGCTAACTCCTTCGTGTATT B18 GGCGTTATCACGGTAATGATTAACAGC B19 ACATCAATCTCTCTGACCGTTCCGC B20 GCCTTATGCTCGAACTGACCATAAC B21 CGGATATCACCACGATCAATCATAGGTAA B22 CCTTAATCTGCTGCAATGCCACAGC B23 TAGCTCTCCGCCTACAATGACGTCA B24 AGGAACGCCTTACGTTGATTATTGA B25 GAGTCAGTACCGATGTAGCCGATAA B26 ACTCGAATGAACCAGGCGATAATGG B27 ATTATATCTGCCGCGAAGGTACGCC B28 GGACAGACAGTGGCTACGGCTCAGTT B29 CGGTATTCGCTTAATTCAGCACAAC B30 GCTCTTACCTGTTGTGCAGATATAA List of HLA DQ capture probe sequences DQ101 CGGGGTGTGACCAGACACA DQ111 CGTCTTGTAACCAGATACA DQ102 GGGTGTACCGGGCAGTGAC DQ112 CGTCTTGTGAGCAGAAGCA DQ103 GCGGCCTAGCGCCGAGTAC DQ113 CGACGTGGAGGTGTACCGG DQ104 GCGGCCTGTTGCCGAGT DQ114 GCCGCCTGACGCCGAGT DQ105 CGTTATGTGACCAGATACA DQ115 GGCCGCCTGCCGCCGAGT DQ106 CGTCTTGTAACCAGACACA DQ116 GACCGAGCGCGTGCGGGGT DQ107 CGTCTTGTGACCAGATACA DQ117 GCTGGGGCGGCTTGACGCC DQ108 GCGGCCTGATGCCGAGTAC DQ118 GGGTGTATCGGGCGGTGAC DQ109 GACCCGAGCGGAGTTGGAC DQ119 GGCGGCCTGACGCCGAGT DQ110 GAGGGGACCCGGGCGGAGT DQ120 CGCTTCGACAGCGACGTGG DQ121 AACCGAGAAGAGTACGTGC

TABLE 4 Pairs of anchor probes showing 3′ similarity A1 GTTGATGTCATGTGTCGCAC A6 ACGTTCGTCAAGAGTCGCAT B25 GAGTCAGTACCGATGTAGCCGATAA B30 GCTCTTACCTGTTGTGCAGATATAA B18 GGCGTTATCACGGTAATGATTAACAGC E22 CCTTAATCTGCTGCAATGCCACAGC A14 CTCGACCGTTAGCAGCATGA B6 GAGACACCTTATGTTCTATACATGC B1 CGCAGGTATCGTATTAATTGATCTGC B14 CTGCACTGCTCATTAATATACTTCTGG A11 ATATCGTGTCACAGGTCGTT B12 TTACAGGATGTGCTCAACAGACGTT

TABLE 5 Revised capture probe sequences with unique 5′ ends DQ101 CGGGGTGTGACCAGACACA DQ102 TTGGGTGTACCGGGCAGTGAC DQ103 TAGCGGCCTAGCGCCGAGTAC DQ104 TTGCGGCCTGTTGCCGAGT DQ105 CGTTATGTGACCAGATACA DQ106 TACGTCTTGTAACCAGACACA DQ107 TTCGTCTTGTGACCAGATACA DQ108 TCGCGGCCTGATGCCGAGTAC DQ109 GACCCGAGCGGAGTTGGAC DQ110 AGAGGGGACCCGGGCGGAGT DQ111 TCCGTCTTGTAACCAGATACA DQ112 GGCGTCTTGTGAGCAGAAGCA DQ113 CGACGTGGAGGTGTACCGG DQ114 CAGCCGCCTGACGCCGAGT DQ115 GGCCGCCTGCCGCCGAGT DQ116 TAGACCGAGCGCGTGCGGGGT DQ117 GCTGGGGCGGCTTGACGCC DQ118 TAGGGTGTATCGGGCGGTGAC DQ119 ATGGCGGCCTGACGCCGAGT DQ120 CGCTTCGACAGCGACGTGG DQ121 AACCGAGAAGAGTACGTGC

Example 7 Multiplex On-Chip Ligation

Table 6 below summarizes the 5-probe system chosen for the multiplexed experiment. The table lists the individual sets consisting of the capture, clamp and the anchor probe and also shows their alignment. TABLE 6 Sequences for the multiplexed ligation experiment DQ107CAPT Phosphate-TTC GTC TTG TGA CCA GAT ACA DQ107ANCH Amine-GTT GAT GTC ATG TGT CGC AC DQ107CLMP ACG AAG TGC GAC ACA 5′-gtt gat gtc atg tgt cgc ac ttc gtc ttg tga cca gat aca-3′ ac aca gcg tg aag ca DQ108CAPT Phosphate-TCG CGG CCT GAT GCC GAG TAC DQ108ANCH Amine-CGT TCC TAA AGC TGA GTC TG DQ108CLMP CGC GAC AGA CTC AGC 5′-cgt tcc taa agc tga gtc tg tcg cgg cct gat gcc gag tac-3′ cg act cag ac agc gc DQ110CAPT Phosphate-AGA GGG GAC CCG GGC GGA GT DQ110ANCH Amine-AAG CCA GAT CGA CCA TCG TA DQ110CLMP CCT CTT ACG ATG GTC 5′-aag cca gat cga cca tcg ta aga ggg gac ccg ggc gga gt-3′ ct ggt agc at tct cc DQ112CAPT Phosphate-GGC GTC TTG TGA GCA GAA GCA DQ112ANCH Amine-ATG ATG TGC AAA GTG CCG TC DQ112CLMP ACG CCG ACG GCA CTT 5′-atg atg tgc aaa gtg ccg tc ggc gtc ttg tga gca gaa gca-3′ tt cac ggc ag ccg ca DQ120CAPT Phosphate-CGC TTC GAC AGC GAC GTG G DQ120ANCH Amine-AGA GCG CAT GAA TCC GTA GT DQ120CLMP AAG GCG ACT ACG GAT 5′-aga gcg cat gaa tcc gta gt cgc ttc gac agc gac gtg g-3′ tt agg cat ca gcg aa The experiment was carried out as follows: Step 1

Coupling of Aminated Anchor Probes to the Beads

The aminated anchor probes (DQ107ANCH, DQ108ANCH, DQ110ANCH, DQ112ANCH and DQ120ANCH) and one negative control probe (N18) were covalently attached to six different color encoded microparticles using EDAC chemistry. They were then used to manufacture several BAS BeadChips.

Step 2

Annealing of Capture Probe and Clamps

The following mixtures were made in five different eppendorf tubes and incubated at 94° C. for 10 minutes followed by cooling to room temperature. Tube 1 Tube 2 Tube 3 Tube 4 Tube 5 1 ul 100 uM 1 ul 100 uM 1 ul 100 uM 1 ul 100 uM 1 ul 100 uM DQ107CAPT DQ108CAPT DQ110CAPT DQ112CAPT DQ120CAPT 1 ul 100 uM 1 ul 100 uM 1 ul 100 uM 1 ul 100 uM 1 ul 100 uM DQ107CLMP DQ108CLMP DQ110CLMP DQ112CLMP DQ120CLMP 18 ul of DI water 18 ul of DI water 18 ul of DI water 18 ul of DI water 18 ul of DI water Step 3

Preparation of the Ligation Master Mix

The ligation reaction mix was prepared by mixing together

-   -   i) 10X Ligation Reaction buffer: 2 ul (New England BioLabs,         Ipswich, Mass.)     -   ii) T4 Ligase enzyme: 1 ul (New England BioLabs, Ipswich, Mass.)     -   iii) 3 ul of each of the annealed product from step 2 (total 15         ul)     -   iv) 2 ul of DI water         Step 4

On-Chip Ligation

The ligation mix (20 ul) prepared in step 3 was added to a BeadChip prepared in step 1 and incubated at RT for 1.5 hr in a humid chamber. Following this the chip was washed thoroughly at room temperature with DI water to strip off the clamp and any un-ligated capture probe. The chip was dried and stored at 4° C. until further use.

Step 5

On-Chip Hybridization

Five oligos (reverse complements of the capture probes listed in Table 6) with a 5′ biotin tag were used as the hybridization targets. 1 uM solutions of each were prepared using 1× TMAC solution. A pooled target mixture was also prepared using 1×TMAC and all the five targets (Final target conc. 1 uM). 20 ul of each target solution was aliquoted onto a separate chip and incubated at 53° C. for 15 minutes. The sample was aspirated off and the chips were then washed with 20 ul 1×SSC buffer with 0.1% SDS at 53° C. for 10 min. Following this the chips were stained with a 1:200 Streptavidin-CY3 solution and washed with 20 ul 1×SSC buffer with 0.1% SDS at RT for 5 min. The slide was then fixed with a fixative solution and finally rinsed with a stop solution and dried. The fluorescent signals were read using a BAS AIS system. The results are shown in Table 7 below. Except DQ108 capture probe (which showed no signal), all other probes performed in a satisfactory fashion. TABLE 7 results of multiplexed on-chip ligation Syn. target Probes (1 uM) HD107 HD108 HD110 HD112 HD120 N_18* DQ107 TAR 491 20 12 12 34 10 DQ108 TAR 15 34 8 11 34 6 DQ110 TAR 30 34 1816 31 52 19 DQ112 TAR 21 25 12 821 42 12 DQ120 TAR 19 22 15 18 703 13 5 target mix 257 97 1634 593 448 36 *negative control probe

Example 8 Design of Multiplex On-Chip Elongation

This preferred embodiment requires a unique set of anchor sequences (each such sequence uniquely associated to an optically decodable code, such as a fluorescently encoded microparticle) and a matched template sequence, that is, a template sequence with a 3′-terminal subsequence that is complementary to the anchor sequence and a 5′-terminal subsequence that is identical to a selected subsequence within a target sequence, for example, a target subsequence comprising a designated variable site of interest. The tag-sequences discussed below in Example 6, with no mutual cross-reactivity and minimal homology to the human genome can be utilized for the anchor sequences of interest. Once the anchor sequences and the target subsequences of interest have been identified, the template sequence is constructed as described above. The process of array modification involves (see FIG. 8) contacting a pool of the template oligos with an array of microparticles pre-functionalized with the anchor oligos in presence of dNTPs or ddNTPs and a DNA-polymerase enzyme in a suitable buffer. The polymerase extends the 3′ end of the anchor sequences in matched anchor-template duplexes in accordance with the 5′ overhang of the template sequence. Finally, the template sequence is de-hybridized leaving behind the newly synthesized ss-oligo, which can now function as the capture probe of interest. It is worthwhile to mention that this particular approach of array modification requires only one unmodified template sequence to be pre-synthesized.

It should be understood that the terms, expressions and examples herein are exemplary only and not limiting, and that the scope of the invention is defined only in the claims which follow, and includes all equivalents of the subject matter of those claims. 

1. A method of creating a carrier-displayed library of oligonucleotide probes by ligation of anchor probes attached to encoded carriers and analyte-specific capture probes, comprising: providing: a. a set of anchor oligonucleotide probes, wherein member probes having different sequences are attached to differently encoded carriers; b. a set of capture oligonucleotide probes which include subsequences complementary to designated analyte sequences; c. a set of clamp probes each having a subsequence complementary to a terminal subsequence of an anchor probe and a subsequence complementary to a terminal subsequence of a capture probe; providing conditions permitting formation of complexes of capture probes and anchor probes, joined by annealing of clamp probes to said respective complementary terminal subsequences; and providing conditions permitting the clamp probes to be released from the complexes.
 2. A method of creating a carrier-displayed library of capture probes in a single multiplex reaction by ligation of a first set of probes (including probes of differing sequences attached to encoded carriers), to a second set of probes having subsequences complementary to an analyte, by forming a complex using a third set of probes capable of annealing to a first subsequence at or near the terminus of members of the first set and a second subsequence at or near the terminus of members of the second set.
 3. The method of claim 2 wherein the capture moiety is an oligonucleotide sequence.
 4. The method of claim 2 wherein the oligonucleotide sequence has a subsequence that is complementary to a subsequence within a target oligonucleotide and has another subsequence that is not.
 5. The method of claim 2 wherein the capture moiety is a peptide.
 6. A method of creating distinguishable probe sublibraries sharing the same carrier color code, the method comprising: attaching, in separate reactions, anchor probes of differing sequence, to carriers of the same color code; functionalizing carriers, via ligation of capture sequences to anchor sequences by way of an intermediate complex involving a set of clamp moieties capable of annealing to exactly one sequence within the anchor sequence set and one sequence within the capture probe set. mixing carriers; and forming a final pool encoded via a combination of the bead associated color and the unique sequence of the anchor probe.
 7. A method of converting an array of encoded microparticles into an application-specific array in a single in-situ ligation reaction, comprising: providing a planar array of encoded carriers displaying type-specific anchor probes; providing sets of: clamps matching an anchor probe sequence and one capture sequence; analyte-specific capture probes; permitting formation of tertiary complex by annealing of anchor probes and capture probes to the clamp; ligating anchor probes to capture probes to form carrier-attached capture probes; and releasing the clamps.
 8. The method of claim 7 providing a first set of probes of differing sequences, attached to encoded carriers, and a second set of probes having an analyte-specific capture moiety, attached by way of an intermediate complex involving a set of clamp moieties capable of annealing to exactly one sequence within the first set and one sequence within the second set.
 9. A method of encoding carriers by combining color coding with sequence tagging to create sublibraries sharing one color code or sharing one tag sequence.
 10. A planar random assembly of oligonucleotides displayed on encoded mciroparticles wherein said oligonucleotides are capable of being converted into unique analyte-specific capture oligonucleotides by in-situ ligation of analyte-specific extension oligonucleotides.
 11. The method of claim 10 wherein the ligation reaction proceeds by way of an intermediate 3-member duplex configuration formed by an encoded oligonucleotide and an extension oligonucleotide, the latter annealing immediately 3′ to the former, to a clamping oligonucleotide.
 12. The method of claim 10 wherein the capture oligonucleotide comprises a sequence substantially complementary to an analyte oligonucleotide present, or expected to be present, in a solution contacting the assembly.
 13. The method of claim 10 wherein the capture oligonucleotide further comprises an “address” sequence that is designed to be dissimilar from any other sequences expected to be present in solution.
 14. The method of claim 10 wherein the capture oligonucleotide is attached to a receptor such as an antigen, antibody, or other protein.
 15. The method of claim 10 wherein the analyte oligonucleotide is a cDNA derived from RNA by reverse transcription.
 16. The method of claim 10 wherein the analyte oligonucleotide is an amplicon derived from gDNA by amplification
 17. The method of claim 10 wherein the analyte oligonucleotide forms a part of an oligonucleotide-peptide chimera.
 18. The method of claim 10 wherein the analyte oligonucleotide forms a part of a protein ligand
 19. A general purpose reagent comprising a planar assembly of oligonucleotide-bearing encoded microparticles, the oligonucleotides capable of being converted into analyte specific capture probes.
 20. A kit comprising: an encoded oligonucleotide array wherein a set of unique encoded oligonucleotides having different sequences are encoded by attachment to differently encoded beads; a set of analyte-specific oligonucleotides; a set of analyte-specific clamps, each having a subsequence complementary to the 5′-terminal subsequence of an analyte-specific oligonucleotide and a subsequence complementary to the 3′ terminal subsequence of a unique encoded oligonucleotide; and a ligase capable of permitting attachment of the termini of an analyte-specific oligonucleotide to the termini of an unique encoded oligonucleotide.
 21. A method of creating a carrier-displayed library of oligonucleotide probes by elongation of a set of anchor probes attached to encoded carriers, said elongation with nucleotides complementary to subsequences of a set of template probes, comprising: providing: a set of anchor oligonucleotide probes, wherein member probes in the set of anchor probes having different sequences are attached at their 5′ ends to differently encoded carriers; a set of template oligonucleotide probes which each include a subsequence complementary to a terminal subsequence in an anchor probe and also include a second subsequence positioned closer towards the 5′ end thereof, said second subsequence being the same as a subsequence in a designated analyte; providing conditions permitting annealing of template oligonucleotide probe subsequences with their respective complementary terminal subsequences and elongation of the anchor probes with deoxy-nucleotide tri-phosphate complementary to the second subsequence to form an elongation product complex; and providing conditions permitting the template oligonucleotide probes to be released from the elongation product complexes.
 22. The method of claim 21 further including the step of providing conditions such that the elongation products anneal to their respective analytes.
 23. The method of claim 21 wherein the carriers are microbeads and the encoding is with an optically detectable signal.
 24. The method of claim 23 wherein the optically detectable signal is color.
 25. A method of converting an array of encoded microparticles into an application-specific array, comprising: providing a planar array of encoded carriers displaying type-specific anchor probes; providing: a set of template oligonucleotide probes which each include a subsequence complementary to a terminal subsequence in an anchor probe and also include a second subsequence positioned closer towards the 5′ end thereof, said second subsequence being the same as a subsequence in a designated analyte; providing conditions permitting annealing of template oligonucleotide probe subsequences with their respective complementary terminal subsequences and elongation of the anchor probes with deoxy-nucleotide tri-phosphate complementary to the second subsequence to form an elongation product complex; and providing conditions permitting the template oligonucleotide probes to be released from the elongation product complexes.
 26. The method of claim 25 providing a first set of probes of differing sequences, attached to encoded carriers, and a second set of probes having an analyte-specific capture moiety, attached by way of an intermediate complex involving a set of clamp moieties capable of annealing to exactly one sequence within the first set and one sequence within the second set.
 27. The method of claim 25 wherein the analyte oligonucleotide is a cDNA derived from RNA by reverse transcription.
 28. The method of claim 25 wherein the analyte oligonucleotide is an amplicon derived from gDNA by amplification
 29. The method of claim 25 wherein the analyte oligonucleotide forms a part of an oligonucleotide-peptide chimera.
 30. The method of claim 25 wherein the analyte oligonucleotide forms a part of a protein ligand 